Light emitting diodes with enhanced thermal sinking and associated methods of operation

Abstract

Solid state lighting devices and associated methods of thermal sinking are described below. In one embodiment, a light emitting diode (LED) device includes a heat sink, an LED die thermally coupled to the heat sink, and a phosphor spaced apart from the LED die. The LED device also includes a heat conduction path in direct contact with both the phosphor and the heat sink. The heat conduction path is configured to conduct heat from the phosphor to the heat sink.

We claim: 
     
       1. A light emitting diode (LED) device, comprising:
 a heat sink; 
 an LED die thermally coupled to the heat sink, the LED die having an emission area; 
 an insulating material in direct contact with the LED die, wherein the insulating material is at least partially transparent; 
 a phosphor spaced apart from the LED die, the phosphor at least partially corresponding to the emission area of the LED die; and 
 means for conducting heat away from the phosphor to the heat sink, wherein the means for conducting heat include:
 first means at least partially opposite the phosphor from the LED die and in direct contact with the heat sink, and 
 second means at in direct contact with both the insulating material and the heat sink. 
 
 
     
     
       2. The LED device of  claim 1  wherein:
 the phosphor includes a first surface and a second surface opposite the first surface; and 
 the first means are in direct contact with the first surface of the phosphor and the second means are in contact with the second surface of the phosphor. 
 
     
     
       3. The LED device of  claim 1  wherein:
 the phosphor includes a first surface and a second surface opposite the first surface; and 
 the means for conducting heat away from the phosphor include means for conducting heat away from the phosphor along a first direction generally parallel to the first and second surfaces and along a second direction generally perpendicular to the first direction. 
 
     
     
       4. The LED device of  claim 1  wherein the means for conducting heat away from the phosphor has a thermal conductivity greater than about 1.0 W/(m·K). 
     
     
       5. The LED device of  claim 1  wherein at least a portion of the means for conducting heat away from the phosphor comprises an at least generally transparent material. 
     
     
       6. The LED device of  claim 1  wherein the means for conducting heat away from the phosphor includes a lateral portion across from a forward-facing surface of the LED die and at least one vertical portion extending from the lateral portion such that the means for conducting heat away from the phosphor at least substantially covers the LED die. 
     
     
       7. The LED device of  claim 1  wherein the heat sink includes at least one of silicon (Si), gallium nitride (GaN), aluminum nitride (AlN), copper (Cu), aluminum (Al), tungsten (W), stainless steel (Fe), diamond (C), glass (SiO2), silicon carbide (SiC), and aluminum oxide (Al2O3). 
     
     
       8. The LED device of  claim 1  wherein the means for conducting heat away from the phosphor includes a plurality of conductive materials positioned in the phosphor. 
     
     
       9. The LED device of  claim 1  wherein the LED die includes an N-type gallium nitride (GaN) material, an indium gallium nitride (InGaN) material, and a P-type GaN material on one another in series. 
     
     
       10. The LED device of  claim 1  wherein the phosphor includes at least one of cerium(III)-doped yttrium aluminum garnet (“YAG”), neodymium-doped YAG, neodymium-chromium double-doped YAG, erbium-doped YAG, ytterbium-doped YAG, neodymium-cerium double-doped YAG, holmium-chromium-thulium triple-doped YAG, thulium-doped YAG, chromium(IV)-doped YAG, dysprosium-doped YAG, samarium-doped YAG, and terbium-doped YAG, CaS:Eu, CaAlSiN3:Eu, Sr2Si5N8:Eu, SrS:Eu, Ba2Si5N8:Eu, Sr2SiO4:Eu, SrSi2N2O2:Eu, SrGa2S4:Eu, SrAl2O4:Eu, Ba2SiO4:Eu, Sr4Al14O25:Eu, SrSiAl2O3N:Eu, BaMgAl10O17:Eu, Sr2P2O7:Eu, BaSO4:Eu, and SrB4O7:Eu. 
     
     
       11. The LED device of  claim 1  wherein the means for conducting heat away from the phosphor includes at least one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and zinc oxide (ZnO). 
     
     
       12. The LED device of  claim 1  wherein the first means and the second means are separated from each other by the phosphor.